Connecting device



May 3, 1966 e. A. FULLER ETAL 3,249,908

CONNECTING DEVICE Filed June 12 1962 3 Sheets-Sheet 1 PR\0R HRT INVENTOR Guanwooo A. FULLER BY CHRL F. \hasaR y 1966 G. A. FULLER ETAL 3,249,908

CONNECTING DEVICE Filed June 12, 1962 3 Sheets-Sheet 2 INVENTOR. GLENLJOOD FLFULLER BYCHRL F. \HESER y 1966 G. A. FULLER ETAL 3,249,908

CONNECTING DEVICE 3 Sheets-Sheet 5 Filed June 12 1962 INVENTOR. GLENuooo H. FULLER BY CARL F. \HESER United States Patent 3,249,908 CONNECTING DEVICE Glenwood A. Fuller, Hershey, and Carl F. Vieser, Mechanicsburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa. Filed June 12, 1962, Ser. No. 201,983 8 Claims. (Cl. 339-98) This invention relates to a device for connecting insulated electrical conductors.

The increased usage of very small electrical conductors has created connecting and terminating problems which can not be adequately handled with existing devices. One problem lies in the fact that the very small conductors are physically difiicult to handle or manipulate with respect to the usual connector components. Another problem is caused by the relatively disproportionate strength of conductor insulating material to that of fine wire employed as the conductor. The foregoing factors are further complicated in situations wherein it is desirable to interconnect fine wire conductors of dilferent diameters or, to connect fine wire conductors to printed circuit conductive paths.

As a partial answer to the foregoing, a novel connecting device employing a tapered serrated post and sleeve arrangement has been developed. An example of such device is described in the US. Patent No. 3,071,750 to James C. Heselwood. The present invention, in part, constitutes an improvement to the Heselwood device and further constitutes an additional and novel solution to other fine wire connecting problems.

It does this through conductive members including a post member adapted to be wedged within an eyelet or sleeve member to entrap one or more conductors there between and terminate such to the conductive material of the members. Either the post or the eyelet member is provided with small serrations extending radially about the member which operate to remove the insulation from conductors. As a basic part of the invention, the post and eyelet members are provided with distinctly different tapers with that of the eyelet member being larger. This feature has been discovered to permit termination of different size conductors by the same post and eyelet assembly at the same time and to preclude accidental snipping off of conductors through the provision of an inherent strain relief to the conductor as it enters into the eyelet member and is terminated. Additionally, this feature permits a Wide variation in insertion force since the post can elfectively terminate a conductor without pinching it off even though forced into the eyelet well beyond the point necessary for termination. The conductor terminated is left in a configuration defined by the difference in taper and which is itself tapered out from a point of near normal thickness to a thinned end. with a broad area of contact interface being defined. In one embodiment of the invention the difference in tapers is carried out by having the taper of the eyelet member constant along its length and in another embodiment by having the taper of the eyelet or post member changed differentially along the length of the taper. This is done through increments which are quite small in one embodiment to provide a smoothly changing taper and in another embodiment through increments which are large to represent distinct steps in a change in taper. In these various embodiments the invention has further aspects through alternative configurations incorporating additional. structure for purposes of accommodating interconnections to provide crimp type terminations and disconnect. type terminations to other conductors and to provide multiple connections.

It is one object of this invention to provide means and method for interconnecting or terminating small conductors.

It is a further object of invention to provide means and method for connecting or terminating small insulated conductors to conductors of different geometries such as the conductive paths of printed circuit boards.

It is a still further object of invention to provide means and method for interconnecting insulated conductors of different diameters.

It is another'object of invention to provide a connecting device for fine insulated conductors without resort to crimping or soldering techniques and with the advantage of component reuse.

It is yet another object of invention to provide a simple and inexpensive connecting device for small insulated conductors requiring relatively simple installation tools.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIGURE 1 is a perspective view of the components of the invention showing the type of interconnection contemplated;

FIGURES 2-2B are enlarged sections of one of the embodiments shown in FIGURE 1;

FIGURES 3-3A are sections of connector and conductor components included to better explain the advantages of the invention;

FIGURES 4-4A are sections of a post and sleeve made in accordance with the prior art;

FIGURES 5-5A, 6-6A, 7-7A and 8-8A each depict component sections for other and separate embodiments of the device of the invention; and

FIGURES 9-17 are further embodiments of the invention including auxiliary connection features.

Referring now to FIGURES 1 and 2 of the drawings, there is shown an insulating board 10 which may beconsidered as similar to the phenolic resin board used with printed circuits or with magnetic core memory frames. Mounted either on or within board 10 are conductive paths 12 and 13 which may be considered as connected to other components mounted on board 10, in turn connected to suitable input or output devices associated with the circuits being formed. Secured to board 10 is an eyelet or sleeve 22 of conductive material having a flange 24 forced into contact with path 12 and forming an opening into which may be inserted a fine wire insulated conductor 14 and a conductive post member 36. In an adjacent path 13, there is a reverse embodiment wherein a post 31 is forced into the board 10 in contact with path 13 forming a means to accommodate a sleeve 23 containing an insulating conductor 15. In the embodiments shown, posts 36 and 31 include a numb-er of fine serrations 40 and 41 forming cutting edges and adapted to cut through the insulation of conductors 14 and 15 and form an electrical contact therewith. The eyelet 22 and the sleeve 23, as well as the posts 30 and 31, include slight tapers so that upon being driven into contact, a tight interlocking fit is formed resulting in the conductors 14 and 15 being electrically and mechanically connected to paths 12,and 13 and to board 10.

In the usual assembly of the device, the board is first punched or drilled and the post or eyelet inserted and flared to form fiangeslocking the particular member within board 10. The board conductive paths are entrapped by such flanges around the member periphery and under a force sufiicient to form a substantial interface connection providing good electrical contact. While the embodiment of FIGURE 1 depicts the conductive paths 12 and 13 as being on the top of the board, it is to be understood that a similar connection could be formed on the bottom of the board or within the board in contact with the post or eyelet body. In the usual practice, printed circuit boards such as are normally made up with posts or eyelets inserted in appropriate conductive paths; the individual complementing member being added along with particular conductors such as 14 and 15 at the time of final assembly of the circuit formed on board 10.

Turning now to a more detailed description, the operative features of the invention will be described with respect to the embodiment wherein the eyelet is inserted in the board.

Following insertion of conductor 14 with 22, post may be forced down into the eyelet in any suitable manner; the upper post portion 30 and flange providing a post gripping means. During the insertion of 30, the tapered post portion 36 including serrations passes downwardly wedging the conductor 14 against the body portion 28 of the eyelet 22 and forming a tight interlocking tit therewith. concomitantly, serrations 40 cut or bite into the conductor 14 piercing the conductor insulation 18 and penetrating well into the conductive material 16 as the conductor is progressively flattened by the post; the leading serrations first cutting through the insulation and then wiping conductive material 16 along its length cleaning away oxidation products and exposing the conductive material to the cutting edges of other serrations.

FIGURE 2A shows an enlarged section of the serrations 40 penetrating the conductive material 16. Each of the serrations 40 is formed of intersecting surfaces to form a cutting edge inclined with respect to the longitudinal axis of the post 30, as indicated by dotted line 42. The post 30 may be considered as having a constant taper indicated by the dotted line 32 and the eyelet 22 may be considered as having a gradually reduced taper as indicated by the dotted line 29. As a result of the difference in tapers and as a result of the serrations 40, the conductor 14 is formed as shown in FIGURE 2B. The conductor insulation 18 is stripped and spread apart under the pressure of insertion of post 30 to form two legs 18A and 18B disposed on either side of the conductive material 16 from the point B to the end of the conductor. The individual serrations form contact areas 20 with the conductive material 16 which gradually increase as the taper of eyelet 22 approaches the taper of post 30. One important result of the difference in taper is depicted in FIGURE 2 wherein the conductor 14 is shown as having a gradual taper from point A along its length which is proportionate to the difference in taper between 22 and 30. This assures that .the conductor thickness will be substantial at the point of greatest stress, namely, at the point of entry into eyelet 22. The dimensions of post 30 and eyelet 22 should thus be selected relative to the given range of conductors to be terminated to provide the difference in taper indicated by lines 32 and 29 so that the tensile strength of conductor and insulating material is gradually reduced along the length of the conductor extending within the sleeve. As shown in FIGURES 2 and 2B, the conductive material 16 is totally insulated by material 18 to a point well within the eyelet 22 and is insulated along its sides by the material 18A and 18B along the entire length of the area of con tact with post 30. In addition to minimizing conductor breakage, the difference in taper thereby improves the insulation of the connection.

As an even more important advantage, the difference in taper contemplated by the invention acts to assure that conductor 14 will not be severed in a manner causing a failure of connection regardless of variations in the force applied to the post in making the connection. In FIG- URE 2 it will be apparent that continued movement of post 30' into the eyelet 22 will further flatten the conductor 14 but will still leave a substantial length of relatively non-flattened conductor within the tapered volume defined by the difference in taper of post and eyelet. This is important in the present invention since the conductor may become flattened to a thickness less than the depth of the serrations; in which event, the application of an excessive force on the post will operate to totally sever the conductor. By providing a larger taper in the eyelet there will exist a considerable number of serrations only partially penetrating the conductor even though the post is driven into the eyelet under a force sufiicient to sever the condoctor at the bottom of the eyelet.

Referring now to FIGURE 3 there is shown the post and eyelet assembly as above described in its use in connecting several conductors of different diameters. In making the connection shown in FIGURE 3, the conductors to be connected are 50, 51 and 52 and it will be apparent that the force necessary to terminate the larger conductor will be greater than that necessary to terminate conductors 51 and 52. By placing the conductors on the same relative side of the assembly and driving the post with a force sufficient to properly terminate conductor 50, the termination of conductors 51 and 52 will be accomplished in the manner indicated in FIGURE 3A, i.e., along progressive sections of the post. It has been found that the differential taper results in a termination of each conductor with a reliable and stable interface connection of low resistance. With the termination shown in FIGURE 3, and with the assembly of the invention in a number of embodiments, the difference in taper and in length of the post and eyelet should result in a width of entry approximating the width of the largest conductor to be terminated and in a width of exit substantially less than half of the diameter of the smallest conductor to be terminated. It has been found that the provision of four or five sizes of post-eyelet assemblies will accommodate the range of conductors most frequently employed.

Referring now to FIGURE 4 there is shown a post 54 and a sleeve or eyelet 58 made in accordance with the prior art. In this assembly, the tapers of post 54 and eyelet 58 are substantially the same as indicated by'the dotted lines 56 and 60. As one result of this, the conductor 62 will be driven into the configuration shown in FIGURE 4A wherein there is a rather severe transition of the conductor diameter at the point of entry into eyelet. As a further result, the conductive material 66 and insulating material 64 are thinnest at the point wherein breakage is most likely to occur. Similarly, the conductive material 66 is less protected by insulation 64 than in the device of the invention as shown in FIGURES 2-2B. It will be apparent that the degree of flattening of conductor 62 will be proportional to the force applied to post 54 and that if such force is excessive, conductor 62 may either be severed or flattened to a point wherein breakage is likely. There is a criticality of insertion force with the device of FIGURE 4 not present in the device of the invention which will accommodate an insertion force of considerable variation. It will be appreciated that components as small as the posts and sleeves herein described have manufacturing tolerances which are extremely ditficult to carry on a production basis. If tolerance variations result in sleeve 58 having less taper than post 54, the foregoing shortcomings will be aggrevated and normal insertion forces will sever the conductor 62. With the device of the invention, as depicted in FIGURE 2, the considerable differences in diameters of eyelet 22 and post 30 at the point of entry will permit substan-' tial tolerance variations without causing a connection failure by severing the conductor 14 at the point of entry into the eyelet. In attempting multiple terminations as in FIGURE 3 with a post and sleeve of equal taper, the

small conductors will frequently be either not terminated or will be only slightly penetrated by the post serrations so that upon being exposed to vibration connection failure will result.

It has been found that diameter and material characteristics of various conductors play an important part in the effectiveness of the post and eyelet technique. The device of FIGURE 2 is operable with round and flat con ductors of various conductive materials and various insulating materials in a Wide range of sizes and therefore may be adapted for general use. The embodiments shown in FIGURES 5-8A constitute useful variations of the technique employed and described relative to the embodiment of FIGURE 2.

Referring first to FIGURE 5; there is shown a post and eyelet 74 each having a taper as represented by the dotted lines 72 and 76, respectively. In this embodiment, the tapers of post and eyelet are constant; the taper of the eyelet being sufficiently larger than the taper of the post to define a relatively large introductory volume. As shown in FIGURE 5A, the conductor 78 is worked into a configuration wherein the conductive material 82 and insulating material assume a configuration linearly related to the difference in taper of post and eyelet and wherein the angle of attack by the post serrations is greater than that in FIGURE 2. This embodiment is particularly useful with larger diameter conductors; the relatively large volume defined by the difference in tapers operating to accommodate the additional conductor material and the increase in serration cutting angle serving to provide an improved penetration. In FIG- URE 6, there is shown an embodiment terminating a conductor 79 wherein post has a constant taper 92 and eyelet 94 includes a taper 96 having defined lengths C and D of different degrees of taper. With conductors of relatively hard insulating material the'section C, having the larger degree of taper, may be made relatively short in length with respect to section D. With conductors having an insulating material which is relatively thick, the sections of different taper may be reversed; i.e., the length C being made longer than the length D to accommodate the extra volume of insulating material.

The post and eyelet assembly of FIGURE 7 includes a post 100 having a constant taper 102 and an eyelet 106 having a reversing taper 104. With the post and eyelet assembly of FIGURE 7, the conductor 108 will be driven to assume the configuration shown in FIGURE 7A with the conductive material 110 substantially surrounded by insulating material 112. In this embodiment, the contact interface is protected to a further extent by conductor insulating material. Furthermore, it has been found that conductors inserted from either or both ends will be satisfactorily terminated.

The embodiments shown in FIGURES 4-7, in addition to the advantages discussed, offer manufacturing advantages in that the different tapers carried in the eyelets are relatively constant along their length. In certain instances and dependent upon the material characteristics of the post and eyelet, such as hardness and ductility, it may be desirable to obtain the advantages of the differential taper in the post; the eyelet being given a constant taper. An example of this is shown in FIGURES 8-8A wherein post 114- is shown to have a taper 116 having distinct sections of different taper along its length. The eyelet 118 includes a constant taper 120 slightly greater than the taper of the center section of the post 114. In the manner heretofore described, the conductor 122 will be driven to assume the configuration shown in FIG- -URE 8A. By varying the taper of post 114, any of the conductor configurations heretofore described can be achieved.

In FIGURE 9 there is shown a further embodiment of the invention which may be utilized with any of the techniques above described to expand the connection capability of the invention. In this embodiment, eyelet 132 is extended in length and includes oppositely opposed tapers 134 and 136 capable of accommodating two post members 124 and 128, each having tapers 126 and 130. With this embodiment, the posts and eyelet entry diameters may be of the same relative size or alternatively, may be of different sizes, i.e., the upper portion of eyelet 132 considerably smaller in diameter than the lower portion with a complementary change in diameter of post members 124 and 128. In the same manner, the upper and llOWCl' portions of the eyelet may be made in different tapers. The embodiment of FIGURE 9 may thus be adapted to accommodate a wide range and number of conductors varying in diameter or material composition.

In FIGURE 10, there is shown yet a further embodiment of the invention wherein the post 140 includes integral and reversed tapered sections 142 and 144 adapted to cooperate with eyelets 146 and 148. In this embodiment the sections 142 and 144 may be identical or may be of either different taper or of differing tapers in the manner of FIGURE 8. The eyelets 146 and 148 may be individually mounted in different printed circuit boards; or, alternatively, only one eyelet may be mounted in a board with the other eyelet being free as in the alternate embodiment shown in FIGURE 1. The post and eyelet assembly of FIGURE 10 may be utilized to achieve not only electrical interconnections with various conductors but also in mechanically stacking printed circuit boards.

FIGURES 11 and 12 show still further embodiments of the invention wherein the post member has an eyelet or sleeve incorporated therein. In FIGURE 11, the post 152 is shown in one possible use with the post base portion 153 secured in a printed circuit board by means of the post flange 154 and a flange 156 formed at the end of the post. The tapered sleeve 158 formed within the post body portion 153 serves to accommodate a further post 160 and permit fine wire terminations of the types heretofore described. The post portion 159 may be utilized to terminate a further conductor through the use of an additional sleeve 162. An alternate use of the post member described with respect to FIGURE 11 is shown in FIGURE 12 wherein the post 164 includes a post portion 165 and a sleeve portion 166. In this embodiment, the post 164 is inserted within an eyelet 168 secured to a board 170 having a printed circuit conducting path 172 contacted by the upper eyelet flange and an auxiliary post 169 is inserted in sleeve 166. It will be appreciated that while the novel post member shown in FIGURES 11 and 12 is depicted as accommodating conductors of the same relative size it is fully contemplated that the post could be made to accommodate larger or smaller conductors at either end. For example, in the embodiment of FIGURE 12, the post portion 165 could be made considerably larger than that indicated with a complementary change in the size of the eyelet 168 and the sleeve portion 166 could be made considerably smaller than that indicated with a complementary change in the auxiliary post 169 inserted within the sleeve.

FIGURES 13 and 14 show other embodiments of the invention further extending the utility of the post and eyelet techniques heretofore described. In FIGURE 13, the member 184 includes a sleeve or eyelet 190 formed as an integral part with a standard pin connector portion 192. The member 184 may be secured to a printed circuit board having a conductive path 182 by means of the flanges 186 and 188. The embodiment shown in FIG- URE 14 would be similarly mounted but with the mem- .ber 200 including fingers 202 and 204 forming a contact portion for another type of standard connector. With the embodiments of FIGURES 13 and 14, extremely fine conductors may be terminated by posts inserted in the sleeve portions and thereby interconnected with relative- 1y large conductors secured to connecting devices adapted to engage members 192 or 202-204.

In FIGURES 15 and 16 there are shown embodiments employing the techniques heretofore described and extending the function of the eyelet member to accommodate crimping techniques. In FIGURE the printed circuit board 210 carrying conductive path 212 is fitted with an eyelet 214- adapted to receive a post and fine wire conductor and further including as an integral part a flange extension 216 forming a crimp barrel 218 adapted to receive a relatively large conductor 220'. FIGURE 15 depicts the assembly following the crimping operation which would normally be performed with the barrel 218 at an angle sufficient to accommodate a crimping tool prior to insertion of the fine wire conductor and post. FIGURE 16 shows a further embodiment wherein the sleeve or eyelet member 222 is secured to a printed circuit board by flanges 2.24 and 226 and is adapted to receive a fine wire and tapered post in the manner heretofore described. Member 222 further includes as an integral part an axially disposed extension 228 adapted to receive relatively large conductor 232 which may be connected thereto by crimping as indicated at 230.

In FIGURE 17 there is shown an embodiment wherein a post 240, having a tapered portion 242, further includes integral extensions forming crimp barrels 244 and 246 disposed at each end. With this embodiment, conductor 250 may be inserted through eyelet 248 into post barrel 246 prior to terminating fine wire 249; conductor 252 thereafter may be inserted in barrel 244 and both conductors crimped in the manner shown. Following this, the fine wire termination may be accomplished in the manner heretofore described. It is, of course, contemplated that post 240 could include only a single crimp barrel if desired. It is further contemplated that one of the crimp barrels shown might be formed at right angles to the longitudinal axis of the post.

The various post and eyelet embodiments above de scribed may be comprised of a number of different conductive materials such as brass, copper or diiferent alloys having similar electrical and material characteristics. Each member should have a sufiicient thickness and hardness' to resist working or deformation which might permit the conductor being terminated to embed itself within either member without being flattened and penetrated in the manner above described. In the foregoing description the serrations have been shown and discussed as being upon the post member. It is contemplated that as an alternative arrangement, the serrations may be formed Within the eyelet or sleeve; the post being smooth. This may be readily accomplished by the forced insertion of a steel mandrel having the desired configuration and including the serrations as shown on the post member in FIGURE 2. With embodiments having reversed tapered portions, the use of separate mandrels inserted from either end of the eyelet will, of course, be required.

In each embodiment shown, the post and eyelet members have each included configurations of circular cross section. It is fully contemplated that the members may be other than circular, for example, square or rectangular in cross section; the differences in taper being maintained in opposing tapered planes on each respective member.

While the eyelet or sleeve has been generally shown as formed of a relatively thin member it is contemplated that the technique of the invention may be extended to terminate fine wires to a wide variety of connectors or conductive materials in general by drilling a tapered pocket of the interior configuration of the eyelet embodiments and employing an appropriate post member.

The differences in taper employed between post and eyelets will differ from embodiment-to-embodiment dependent upon the diameter and configuration of the conductor to be terminated as well as the material characteristics of such conductors. In an actual embodiment made in accordance with FIGURE 2 for accommodating triple Formvar coated conductors ranging in size from No. 32

AWG to No. 56 AWG, the diiference in taper varied from approximately S'degrees at the mouth of the eyelet to approximately 2 degrees, one-quarter of the distance into the eyelet, thereafter gradually diminishing to approximately zero degrees at the bottom of the eyelet. In this embodiment, the entry and exit diameters were .037 and .045 inch, respectively, for the post and .040 and .047 inch respectively, for the eyelet. The post was provided with serrations extending .100 inch; each serration being approximately .010 inch long and .0005 inch deep. The eyelet of the unit was comprised of tin plated brass and the post was comprised of tin plated commercial bronze. The unit was utilized to satisfactorily terminate conductors of three different diameters having three different insulating materials. Similar units have been employed to accomplish as many as five repeated connections with different conductors in a satisfactory manner.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may .be made without departing from the scope of the invention. The matter set forth in the foregoing description .and accompanying drawings is olfered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

We claim:

1. A connecting device including a post member and sleeve member of deformation resistant conductive material each having tapered portions; one of the members including a series of serrations, the said post and sleeve members being adapted for engagement with the post member being wedged in said sleeve against one or more conductors to be terminated such that the said serrations bite into the one or more conductors to provide a low resistance stable interface with the member carrying said serrations, the sleeve member having a taper in its tapered portion larger than the taper of the tapered portion of the post member to define a space between the post member and sleeve member when the post member is engaged 'within the sleeve member, which space increases from one end of the members toward the point of entry of the one or more conductors such that the one or more conductors are deformed in a tapering configuration between the outside surface of the post member and inside surface of the sleeve member in a sense of taper like thatof the said members and to provide a strain relief for said conductors.

2. In an electrical connection the combination comprising a conductive post member of deformation resistant metal having a portion of an outer surface extending longitudinally along the length thereof and of a given taper, a conductive sleeve member of deformation resistant metal surrounding said post member and having .an inner surface extending longitudinally along the sleeve length and of a taper larger than said given taper to define a space between the post and sleeve members when the post member is fitted into the sleeve member, which space increases from one end of the members to the other end of the members to serve as an entry of a conductive lead into .a said space between said members, a series of serrations forming cutting edges extending around the surface of one of said members in a sense transverse to the longitudinal axis thereof, at least one conductive lead fitted within said space from said other end of said members and extending therealong between the outside sunface of the post member and the inside surface of the sleeve member with the said post member being axially driven relative to said sleeve member to substantially deform said lead along the length within said sleeve into a tapered configuration tapering in the same sense of taper as said members and of decreasing thickness as measured from the entry of said lead and of increasing area of contact with the serrations of said one member and to wedge said post into an interlocking frictional fit within said sleeve to entrap and terminate said lead to one of said members.

3. The connection of claim 2 wherein the said given taper of the post member is substantially constant along the length thereof and the taper of the sleeve member is gradually diminished along the length thereof.

4. The connection of claim 2 wherein the said given taper of the post member and the taper of the sleeve member are each substantially constant along the length thereof.

5. The connection of claim 4 wherein the said lead includes an insulating sheath and the said post member includes further portions on each end adjacent said outer surface with each further portion having a cross-sectional dimension less than that of the adjacent portion of the said outer surface such that the said .area of contact with said lead is surrounded 'by insulationj 6. The connection of claim 2 wherein the conductive lead has an insulating sheath and the said sleeve member inner surface includes .a further portion of a reverse taper relative to said first mentioned sleeve taper such that the conductive lead as it extends through the said sleeve has the said area of contact surrounded by insulation.

7. The connection of claim 2 wherein the said sleeve member includes an integral extension adapted to form a connection with a further lead.

-10 8. The connection of claim 2 wherein the post member includes an integral extension adapted to form a connection with a further lead.

References Cited by the Examiner UNITED STATES PATENTS 2,428,083 9/1947 Kolstad 339-400 X 2,686,963 8/1954 Freyssinet 24126 X 2,692,422 10/1954 'Pierce 17490 X 2,799,838 7/1957 Kribs 339-99 2,913,634 11/1959 Scoville 339-2 20 X 2,915,678 12/1959 Frazier et al '33-9-l7 X 2,990,533 6/1961 Hughes et a1. 33995 X -3,014,140 12/1961 Tupper 339-97 X 3,058,764 10/ 1962 Scott et a1 28720.3 3,060,258 10/ 1962 Spurgeon l747 3,071,750 1/ 1963 Heselwood 339- 97 3,085,305 4/ 1963 Colombet et al 24126 3,093,887 6/1963 Prestige et al 339-221 X PATRICK A. CLIFFORD, Primary Examiner.

W. DONALD MILLER, Assistant Examiner. 

1. A CONNECTING DEVICE INCLUDING A POST MEMBER AND SLEEVE MEMBER OF DEFORMATION RESISTANT CONDUCTIVE MATERIAL EACH HAVING TAPERED PORTIONS: ONE OF THE MEMBERS INCLUDING A SERIES OF SERRATIONS, THE SAID POST AND SLEEVE MEMBERS BEING ADAPTED FOR ENGAGEMENT WITH THE POST MEMBER BEING WEDGED IN SAID SLEEVE AGAINST ONE OR MORE CONDUCTORS TO BE TERMINATED SUCH THAT THE SAID SERRATIONS BITE INTO THE ONE OR MORE CONDUCTORS TO PROVIDE A LOW RESISTANCE STABLE INTERFACE WITH THE MEMBER CARRYING SAID SERRATIONS, THE SLEEVE MEMBER HAVING A TAPER IN ITS TAPERED PORTION LARGER THAN THE TAPER OF THE TAPERED PORTION OF THE POST MEMBER TO DEFINE A SPACE BETWEEN THE POST MEMBER AND SLEEVE MEMBER WHEN THE POST MEMBER IS ENGAGED WITHIN THE SLEEVE MEMBER, WHICH SPACE INCREASES FROM ONE END OF THE MEMBERS TOWARD THE POINT OF ENTRY OF THE ONE OR MORE CONDUCTORS SUCH THAT THE ONE OR MORE CONDUCTORS ARE DEFORMED IN A TAPERING CONFIGURATION BETWEEN THE OUTSIDE SURFACE OF THE POST MEMBER AND INSIDE SURFACE OF THE SLEEVE MEMBER IN A SENSE OF TAPER LIKE THAT OF THE SAID MEMBER AND TO PROVIDE A STRAIN RELIEF FOR SAID CONDUCTORS. 